public class Student implements Comparable<Student>{

    public String name;
    public int age;

    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    @Override
    public int compareTo(Student o) {
//        if (this.age>o.age)
//            return 1;
//        else if (this.age<o.age)
//            return -1;
//        else return 0;
        return this.age-o.age;

//        return this.name.compareTo(o.name);
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}
